Vanessa, Sabrina and Yoko had 936 coins. Sabrina won some of the coins from Vanessa and as a result, Sabrina's coins increased by 50%. Yoko then won some coins from Sabrina and Yoko's coins increased by 75%. Finally, Yoko lost some of her coins to Vanessa and Vanessa's coins increased by 20%. In the end, they realised that they each had an equal number of coins. How many percent less did Vanessa have in the end than what she had at first? Correct your answer to 1 decimal place.

Vanessa	Sabrina	Yoko
936
	2 u
- 1 u	+ 1 u
	3 u
		4 p
	- 3 p	+ 3 p
		7 p
5 boxes
+ 1 box		- 1 box
6 boxes
1 group	1 group	1 group

50% = ⁵⁰₁₀₀ = ¹₂
75% = ⁷⁵₁₀₀ = ³₄
20% = ²⁰₁₀₀ = ¹₅

Working backwards.

3 groups = 936

1 group = 936 ÷ 3 = 312

1 group = 6 boxes
6 boxes = 312

1 box = 312 ÷ 6 = 52

1 group + 1 box = 7 p
312 + 52 = 7 p
7 p = 364

1 p = 364 ÷ 7 = 52

3 p = 3 x 52 = 156

1 group + 3 p = 3 u
312 + 156 = 3 u
3 u = 468

1 u = 468 ÷ 3 = 156

Number of coins that Vanessa had at first
= 5 boxes + 1 u
= (5 x 52) + 156
= 260 + 156
= 416

Percent that Vanessa had less in the end than at first
= ^{416 - 312}₄₁₆ x 100%
≈ 25.0%

Answer(s): 25.0%